I think the burden of proof is on those who assert that China has ever been meaningfully socialist. After the 1949 revolution, even under Mao, the bourgeoisie continued to exist. Mao asserted the "national bourgeoisie" could help in the construction of socialism:
"In our country, the contradiction between the working class and the national bourgeoisie comes under the category of contradictions among the people. By and large, the class struggle between the two is a class struggle within the ranks of the people, because the Chinese national bourgeoisie has a dual character. In the period of the bourgeois-democratic revolution, it had both a revolutionary and a conciliationist side to its character. In the period of the socialist revolution, exploitation of the working class for profit constitutes one side of the character of the national bourgeoisie, while its support of the Constitution and its willingness to accept socialist transformation constitute the other. The national bourgeoisie differs from the imperialists, the landlords and the bureaucrat-capitalists. The contradiction between the national bourgeoisie and the working class is one between exploiter and exploited, and is by nature antagonistic. But in the concrete conditions of China, this antagonistic contradiction between the two classes, if properly handled, can be transformed into a non-antagonistic one and be resolved by peaceful methods. However, the contradiction between the working class and the national bourgeoisie will change into a contradiction between ourselves and the enemy if we do not handle it properly and do not follow the policy of uniting with, criticizing and educating the national bourgeoisie, or if the national bourgeoisie does not accept this policy of ours."
("On The Correct Handling Of Contradictions Among The People" - February 1957)
Mao's position was very similar to that of Bukharin who believed that exploiting classes could "grow into" socialism. Obviously, this position was rejected by Stalin and the CPSU on the grounds that it was erroneous and counter-revolutionary.
In my opinion, the Chinese Revolution stalled at the bourgeois-democratic phase. This does not negate the fundamentally progressive nature of the revolution (which was both anti-imperialist and anti-feudal) but there is no meaningful evidence to suggest that it ever definitively passed-over into the socialist revolution. Nevertheless, the Chinese leadership continued to use Marxist-Leninist language in justifying its policies, in order to placate its working-class and in order to maintain the support of the Soviet Union (until the Sino-Soviet Split) and the international communist movement.